This invention relates to devices for the clinical detection of biological particles by the utilization of the phenomenon by which such biological particles interact specifically either immunologically or non-immunologically.
Constructions of diagnostic devices for use in the immunological detection of proteins are disclosed in U.S. patent application Ser. No. 384,113 -- Giaever, filed July 30, 1973 (now abandoned) and U.S. Pat. No. 3,926,564 -- Giaever. In both of these constructions the outer surface consists of a layer of preselected proteins specifically interactive with the protein of interest. In Ser. No. 384,113, the substrate surface to which the preselected protein layer is applied is preferably a metallic coating on a glass substrate. In U.S. Pat. No. 3,926,564, the surface to which the preselected protein layer is applied is made up predominately of metallic oxide, which metallic oxide may contain minute metallic particles. The aforementioned application was assigned to the assignee of this invention. Both the aforementioned Giaever patent and Giaever application are incorporated herein by reference.
In still another diagnostic device described and claimed in U.S. Pat. No. 3,979,184 -- Giaever, a non-transparent surface of metal (solid metal or non-transparent coating of metal on a different substrate), which is a comparatively poor reflector of light, is covered with a thin transparent first layer of dielectric material. This first layer, in turn, has a transparent second layer of metal adhered over the outer surface thereof. U.S. Pat. No. 3,979,184 is also incorporated by reference.
Most antigens are proteins or contain proteins as an essential part, whereas all antibodies are proteins. Proteins are large molecules of high molecular weight, i.e., are polymers consisting of chains of variable numbers of amino acids. A given proteinaceous material will comprise entities (e.g., protein molecules, cells, etc.), which do not adhere to each other. Therefore, when a proteinaceous material is brought into contact with a substrate, it deposits as a single layer. If the entities are molecular in size, the resulting single layer is monomolecular. No other arbitrary protein will adhere to an already deposited protein layer. On the other hand, a protein that is specifically reactive relative to a protein that has been adsorbed onto the substrate will immunologically bond thereto. In accordance with the teachings of the above-cited applications, this discovery is exploited to provide medical diagnostic apparatus in which a slide having a first layer of one protein adsorbed thereon is used to test suspected solutions for the presence of the protein specifically reactive thereto. If the specifically reactive protein is present in the solution, the slide (after exposure to the solution) will have a double protein layer thereon. If the specifically reactive protein be absent from the solution, the slide (after exposure to the solution) will have only the original layer thereon.
The term "biological particle" is intended to encompass smaller proteins (e.g., plasma proteins, antigens, antibodies, lactins) and bodies of proteinaceous material (e.g., viruses, bacteria, cells) capable of stimulating antibody production, when injected into an animal, and/or having the property of interacting specifically either immunologically or non-immunologically.
The term "antigenic material" and the term "antigenically active material" describe material containing antigenic sites such as may be derived from viruses, bacteria, etc.
Reference herein to "visual readout" means readout that can be accomplished by a person with normal vision (or vision correctible to 20/40) who is not color blind and is unaided by instrumentation.